It is obvious that there would be an advantage in having jewelry—rings, bracelets, necklaces and the like—that are adjustable in length, diameter, etc.
For the jeweler, it would mean that these items can be inventoried as one size fits all.
For the wearer, if the means used for adjustment were simple enough, it would mean that as the size of fingers or wrists change with age or weight, the size of a ring or necklace could be adjusted by the wearer, thus eliminating the need to go back to the jeweler. One could even decide in an instant to wear a ring on a different finger. It is not unknown for it being necessary for a ring to be cut off the wearer. There are some people that cannot realistically wear rings at all due to proportionately large digital bone joints between the middle phalanx and proximal phalanx; those individuals would be able to enjoy the novel experience of wearing such jewelry on their fingers.
It would also mean that as styles change, or particular clothing is worn for a specific occasion, or even on whim, the wearer could change the length of a necklace or earrings. It would actually be exciting if the wearer could easily make the changes while actually wearing the piece—changing one's appearance while looking at one's self in a mirror or even during a short reparation in the middle of an occasion.
The prior art includes many patents on expandable, adjustable jewelry, but the means used to accomplish expandability and adjustability are somewhat primitive, and, most importantly, do not allow an adjustment to be quickly made or even while the piece of jewelry is being worn.
From 1882 (U.S. Pat. No. 0,263,920 to LaGrange) until the present, expandable rings and bracelets have used the rack and pinion principle or derivatives and/or more chic versions thereof. Recently these include—only as examples among many—U.S. Pat. No. 3,910,067 (1975) [Rumbaugh], U.S. Pat. No. 4,753,087 (1988) [D'Annunzio], U.S. Pat. No. 5,412,956 (1995) [Levy], U.S. Pat. No. 5,419,159 (1995) [Muller], U.S. Pat. No. 5,605,059 (1997) [Woodward], U.S. Pat. No. 6,032,485 (2000) [Steinberg], and U.S. Pat. No. 6,085,550 (2000) [Ishida].
U.S. Pat. No. 6,442,970 (2002) [Dangelmayer, et al], uses more sophisticated means to the end, but does not deliver the advantages of the current invention.